Modeling the effect of wheeled tractors and skidded timber bunches on forest soil compaction

An increasing demand for forest products incites a large number of log transportation operations, which may lead to negative consequences for the soil and the ecosystem as a whole. This paper is focused on establishing a mathematical model to estimate the soil deformation and compaction processes under tires of wheeled forest machines and individual components of the skidding system such as forwarder, limbs, butts, and tops of tree-lengths in high latitudes, permafrost soil and forests. The method applied is based on simulating the impact processes of elastic tires and the skidding system on the soil through a mathematical device for the measurement of the compaction parameters for different types of soil and the size of the shelterbelt. The effectiveness of the proposed models was evaluated according to experimental results. The influence of the rheological (elastic, viscous, and plastic) properties of soil were studied. The elasticity of tires and the running speed of forest machines can help to control the performance of forest machines. This can be done by reducing the pressure exerted on the soil and increasing the number of skidder passes 1.5-2-fold. Comparative analysis showed that the calculated data differ from the experimental ones by no more than 10%. The obtained results and the developed model will allow for a qualitative and quantitative assessment of technological impact on the soil during the projecting maps for logging operations. © 2021 Institut za Istrazivanja. All rights reserved

Improving the efficiency of forest companies by optimizing the key indicators of sustainable forest management: a case study of the Far East

Forest plantations provide a wide range of products. Therefore, it is vital to ensure the sustainable growth and adequate management of forest resources. This study aims to examine the current challenges facing the forest industry, such as the depletion of forest resources, the increasing cost of wood processing products, and intensifying competition in the timber market (caused by the tropical wood supply). These challenges force the world’s leading forest countries to intensify forest cultivation, to consult forest industries in the Far East and to optimize the sustainable use of forest resources. It was found that current distribution of cutting practices threatens the forest ecosystem. The study suggests a scheme where 10–30% of forest area is clear-cut, 70–90% is selectively logged, and 20–35% is exposed to gradual felling. Factors, such as harvesting time, exhaust emissions, the loss of young trees, topsoil degradation, load on the soil surface, and the slope angle are essential for building mathematical models of forest sustainability. The intensity of wood transportation is also a critical factor influencing the above indicators. The study proposes a model for reorganizing regional wood harvesting companies to improve their profitability. The theoretical model is adapted to the Far Eastern context, but is suitable for use in other parts of the world. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group

Predicting the Passability of Wheeled Tractors

Assessment of the tractor's passability plays an essential role in determining its capability to move under certain conditions. However, the operation of forest machinery may lead to soil deformation and degradation of its mechanical properties. Consequently, this study aims to develop a mathematical model for the tractor's crosscountry capability assessment and its impact on the soil. A predictive model was created as part of the study, which depends on the soil and the forwarder parameters. Some high-correlation dependencies of deformation modulus and cone index, specific tractive force, internal friction angle, and shear modulus on these parameters were established. The developed model can be used to analyze changes in rut depth and soil compaction factors after multiple tractor passages. Soil moisture content and temperature can influence the deformation rate, as drier and warmer soils tend to deform much faster. Furthermore, the proposed model can analyze the impact of forestry and agricultural machinery on soils. © 2022, Mathematical Modelling of Engineering Problems. All Rights Reserved